That station is said to be one of the signals used by the UK’s nuclear subs to assess the state of the country in a war scenario.
https://en.wikipedia.org/wiki/Letters_of_last_resort#:~:text...
Long Wave radio era set to end with switch-off
11–20 of 170 posts
Re: Long Wave radio era set to end with switch-off
#12The Droitwich transmitter used to transmit on exactly 200 kHz which I always thought was very cool, but it moved to 198 kHz in 1988 to better harmonize with European stations. The program was mostly the same as BBC Radio 4 but it used to diverge at certain times of day. I used to be woken up at 5am every day by my parents clock radio with the farming news which was very dull, but easy to sleep through.
Thanks for mentioning the actual frequency. The article says "long wave" many times without specifying what it actually means.
Re: Long Wave radio era set to end with switch-off
#13The Droitwich transmitter used to transmit on exactly 200 kHz which I always thought was very cool, but it moved to 198 kHz in 1988 to better harmonize with European stations. The program was mostly the same as BBC Radio 4 but it used to diverge at certain times of day. I used to be woken up at 5am every day by my parents clock radio with the farming news which was very dull, but easy to sleep through.
It was my father's morning alarm, too. But he was a couple of thousand miles away in New York state. That, and Atlantic 252 (I believe now long gone) were what he woke up to every morning.
Despite the name I would not have guessed you could pick up Atlantic 252 in the US. The quality of it wasn't great for listening to music.
https://en.wikipedia.org/wiki/Atlantic_252
"Although the transmitter was in Ireland, the signal's reach meant that it was often looked upon as a "UK national station". Reception reports were received from such locations as Berlin, Finland, Ibiza and Moscow."
Re: Long Wave radio era set to end with switch-off
#14That is too bad, you would think these could be kept active for historical purposes. But seems these services are all being turned off even though I heard a few were very useful in this day and age.
IIRC, their operation relies on enormous vacuum tubes that the BBC can’t get replacements for any more.
Re: Long Wave radio era set to end with switch-off
#15Seems like everyone's shutting down radio services. CHU and Weather radio in Canada too :(
These transmitters consume insane amounts of power. Per Wikipedia, that's 500 kW of rated transmission power for this one [1], so probably a solid megawatt of grid power input. At 30 ct/kWh, that's 300€ per hour, 7200€ per day and about 2.6 million € a year - for a customer base that is only decreasing. [1] https://en.wikipedia.org/wiki/Droitwich_Transmitting_Station
Doesn't excuse CHU: two 3kW, one 5kW ERP.
And by the virtue of shortwave propagation, it could be heard across the world. For the past month and a half (from when the news of its impending shutdown was revealed) I was regularly picking it up in Australia right up until the bitter end.
Re: Long Wave radio era set to end with switch-off
#16Earlier quoted context omitted.
These transmitters consume insane amounts of power. Per Wikipedia, that's 500 kW of rated transmission power for this one [1], so probably a solid megawatt of grid power input. At 30 ct/kWh, that's 300€ per hour, 7200€ per day and about 2.6 million € a year - for a customer base that is only decreasing. [1] https://en.wikipedia.org/wiki/Droitwich_Transmitting_Station
Is that emitted power, consumed power, or effective radiated power? Without knowing that, your power calculations have no meaning. Radio stations are usually measured by the last of those: Effective radiated power. You can have a radio station with a 50,000 watt ERP, but running only a 2,500 watt transmitter. For FM radio stations, it's all about the height of the transmitter above average terrain. For AM, it's about…
Also bear in mind that Droitwitch is radiating 3 different services. Talk Sport (1053 kHz), Radio 4 (198 kHz) and Radio Five Live (693 kHz).
My suspicion is that this means an exciter and a stack of amps per service, which then go through a two stage combiner and out to the antenna. There might even be a pair of exciters and amps per service depending on redundancy.
The combiners (certainly for FM/DAB/TV services) also cause cumulative attenuation as the signal gets combined each time, so even if all 3 are radiating at the same power, the first in the chain might need twice as much amplification to make up for losses.
edit: MB21 (of course) has some fantastic technical info about Droitwitch: https://tx.mb21.co.uk/gallery/gallerypage.php?txid=1454&page... and there's some great pics here, too: https://www.radiorewind.co.uk/radio1/droitwich.htm
I believe they're still using a pair of Marconi B6042 transmitters (250kW each, in parallel) to provide at least one of the services.
Re: Long Wave radio era set to end with switch-off
#17That is too bad, you would think these could be kept active for historical purposes. But seems these services are all being turned off even though I heard a few were very useful in this day and age.
IIRC, their operation relies on enormous vacuum tubes that the BBC can’t get replacements for any more.
In some way it is short-sited, as radio is a good backup medium for global communications in case the entire Internet ever goes down.
Vacuum tubes also aren't vulnerable to nuclear weapon electro-magnetic pulses.
However, other than ham radio enthusiasts I guess no one listens to analogue radio anymore.
Re: Long Wave radio era set to end with switch-off
#18The Droitwich transmitter used to transmit on exactly 200 kHz which I always thought was very cool, but it moved to 198 kHz in 1988 to better harmonize with European stations. The program was mostly the same as BBC Radio 4 but it used to diverge at certain times of day. I used to be woken up at 5am every day by my parents clock radio with the farming news which was very dull, but easy to sleep through.
Thanks for mentioning the actual frequency. The article says "long wave" many times without specifying what it actually means.
"Longwave", usually written without a space, is an informal and not well-defined term for radio frequencies lower than the AM broadcast band, which in Europe is known as "medium wave".
In the USA there have never been commercial longwave stations, though various WWV time signals are broadcast in that band.
Re: Long Wave radio era set to end with switch-off
#19Earlier quoted context omitted.
These transmitters consume insane amounts of power. Per Wikipedia, that's 500 kW of rated transmission power for this one [1], so probably a solid megawatt of grid power input. At 30 ct/kWh, that's 300€ per hour, 7200€ per day and about 2.6 million € a year - for a customer base that is only decreasing. [1] https://en.wikipedia.org/wiki/Droitwich_Transmitting_Station
Is that emitted power, consumed power, or effective radiated power? Without knowing that, your power calculations have no meaning. Radio stations are usually measured by the last of those: Effective radiated power. You can have a radio station with a 50,000 watt ERP, but running only a 2,500 watt transmitter. For FM radio stations, it's all about the height of the transmitter above average terrain. For AM, it's about…
> Is that emitted power, consumed power, or effective radiated power?
Going by [1], emitted power.
[1] https://www.bbceng.info/Operations/transmitter_ops/Reminisce...
Re: Long Wave radio era set to end with switch-off
#20That is too bad, you would think these could be kept active for historical purposes. But seems these services are all being turned off even though I heard a few were very useful in this day and age.
IIRC, their operation relies on enormous vacuum tubes that the BBC can’t get replacements for any more.
We do spend out quite a lot here in the UK for the BBC. They could easily dump a couple of expensive presenters and use the savings for vacuum tubes, if that is what is needed.
No idea where vacuum tubes were invented but I'm sure the BBC could find someone to make them.